Micro-optical systems employ optical elements that typically range in size from a few microns to a few millimeters and are used in a variety of optical and optical-electrical technologies and applications that require a small foot print or small form factor. With the increasing miniaturization of many types of optical and optical-electrical devices and systems, increasing demands are being placed on the size, performance, and integration requirements of micro-optical systems.
An example application where micro-optical systems are seeing increased use and increasing demands on size, performance, and integration is optical telecommunications. As high-speed optical telecommunications and data communications evolve, multiple wavelength channels are becoming widely adopted even in short-distance data center applications. As a result, multiplexer/de-multiplexer (Mux/DeMux) devices that employ micro-collimators and optical wavelength filters are becoming an important component in optical modules, such as C-form factor pluggable (CFP) optical modules, to functionally combine/split multiple optical signals each operating at a designated wavelength into/from a common input/output (I/O) optical fiber.
The ever-increasing demands for greater bandwidth is driving the telecommunications industry toward greater number of wavelength channels. Adding to this trend, the dimensions of the optical transceivers are decreasing dramatically, requiring increasingly smaller micro-optical beam collimators and pitches between adjacent channels to keep the size of the WDM device as small as possible. Further, increasing demands for greater device reliability calls for the use of fabrication techniques that keep the optical components in the WDM device in relative alignment. In addition, the micro-optical beam collimators occupy significant space in WDM and largely define the device form factor while also playing a key role in device reliability and optical performance.